* Unmount operation should not fail if volume is already unmounted ([#38547](https://github.com/kubernetes/kubernetes/pull/38547), [@rkouj](https://github.com/rkouj))
* Updates base image used for `kube-addon-manager` to latest `python:2.7-slim` and embedded `kubectl` to `v1.3.10`. No functionality changes expected. ([#42842](https://github.com/kubernetes/kubernetes/pull/42842), [@ixdy](https://github.com/ixdy))

- **API Machinery**
  - [beta] `kube-apiserver` support for the OpenAPI spec is moving from alpha to beta. The first [non-go client](https://github.com/kubernetes-incubator/client-python) is based on it ([kubernetes/features#53](https://github.com/kubernetes/enhancements/issues/53))
- **Apps**

            <![CDATA[
            Specifies the language of the source files - typically {@code java} or {@code resources}.
            Resources is used as a generic term for scripting languages (e.g., JavaScript or Python)
            or markup languages (e.g. properties file, <abbr>JSON</abbr> or <abbr>XML</abbr>).

            <p>The <b>java</b> language is used for specifying a directory containing the Java sources of the project.

    /** The key of the message: Properties File */
    public static final String LABELS_facet_filetype_properties = "{labels.facet_filetype_properties}";

    /** The key of the message: Python */
    public static final String LABELS_facet_filetype_python = "{labels.facet_filetype_python}";

    /** The key of the message: Ruby */